Recruitment process not good - they rejected me without feedback and sent a generic email to say it was a task I did - but I didn't have to do any tasks for the role so not sure what's going on?

In the beginning asked me to introduce myself. Then usual questions about resume, experiences, and understanding about the role, the firm. Finished by asking if I had any questions for them.

Absolutely horrendous, went through a three week interview process with various tests, when it came to the final interview they decided to completely ignore me without providing any feedback nor even a rejection email, just outright ghosting. I honestly do not understand how a firm this large can engage in such unprofessional behavior.